On the surface, having a former two-term governor running for an open seat (GOP Sen. Bob Corker is not running for re-election) looks like a great takeover opportunity for Democrats, but there are some signs that the race should still be considered a long shot.

Tennessee has shifted to the right and Bredesen hasn’t faced a real challenge in years.

It’s hard to believe that George W. Bush defeated Vice President Al Gore just 51-47 percent in 2000, although Gore was a former senator from Tennessee. Bush did better four years later with a 57-43 percent victory over John Kerry, which was close to John McCain’s 57-42 percent win over Barack Obama in 2008 on what was arguably Democrats’ best night in a decade. Mitt Romney bested Obama 59-40 percent in 2012 and Trump won 61-35 percent in the last presidential race.

The news isn’t much better for Democrats at the state level. Republicans have four times the number of state senators and twice the number of state representatives now compared to 2002, when Bredesen was first elected governor.

In that 2002 race, Bredesen nearly doubled GOP Rep. Van Hilleary in spending (including millions of dollars from his own checkbook) and Hilleary was saddled with deeply unpopular GOP Gov. Don Sundquist, who was term-limited. Bredesen won 51-48 percent. His re-election race was never considered competitive and he won 68-30 percent over state Sen. Jim Bryson in a national Democratic wave.

Bredesen hasn’t been tested as a candidate in over a dozen years and never been tested in a federal race. As the Democratic nominee, he’ll have to fend off connections to Hillary Clinton and Barack Obama.

But it’s not even clear Bredesen is Democrats’ best candidate. Attorney and Iraq War veteran James Mackler has been in the race for months, raised $761,000 through the end of September and finished the third quarter with a modest $321,000 cash on hand. But he would give Democrats a fresher face and a political outsider who isn’t as easily connected to partisan politics.

While there are similarities to former Indiana Sen. Evan Bayh or Nebraska Sen. Bob Kerrey—two retired politicians who lost comeback attempts—the better comparison might be Ohio in 2016. Former Gov. Ted Strickland entered the race with Democratic hopes and dreams but needed some help from the party establishment to get past young Cincinnati City Councilman PG Sittenfeld 65-22 percent in the Democratic primary and was crushed by GOP Sen. Rob Portman 58-37 percent in the general election.

Democrats have benefited from competitive GOP primaries in the past in other states. But in a Republican field which includes Rep. Marsha Blackburn, former Rep. Stephen Fincher, and others, it looks less likely Republicans will choose an unelectable nominee.

Of course the Tennessee race is worth watching, and Bredesen might start the race within striking distance. But his highest point in the race might be the day he officially announces. We’re keeping our Solid R rating for now and will wait to see how the race and the cycle develops.